Apparatus for the uninterrupted separation of constituents.



F. W. ILGES. A APPARATUS FOB TEE UNINTEBBUPTED SEPARATION 0F UONSTITUBNTS.

Anruurrmn Imm nu 4, 1909.

968,478. Y Patented Aug. 23, 1910.

UNITED STATES PATENT oFFioE.

APPARATUS FORTHE UNINTERBUPTED SEPARATION OF CON'SI'LI'JPfLI'IEINTS.l

l Speoication of etters Patent. Patented Aug. 2,3, 1910.

Application led May 4, 1909. Serial No. 493,978.

rectifying columns in a certain arrangement and succession.

In the drawing-the figure is a diagrammatic representation of the apparatus.

Referring to the figure,A1 and A2 are distilling columns provided in their lower parts with the heaters AVl and Av2. These heaters are preferably heated by steam passing through a coil of pipes in the well-known way, though if the character of the fluids to be se arated permits, steam may be introduce directly into such fluids. The columns B2, C1, B2 and C2 are rectifying col-` umns consisting of dephlegmators and rectiers, which do not require any special condensers; but it is evident that any other form of rectifying column may be used. The two rectifying-columns B1 and B2 are each provided in their lower part with evaporators BVl and BV2, each having a system of steam-heated pipes or other steam-heated surfaces therein; these evaporators being arranged in such manner that the condensate flows over the heating surfaces of the evaporators and thence back through the pipes r1 or 7'2 into the distilling column These evaporators may however also, without their action being thereby impaired, be fitted, as shown in dotted lines at BV and BV2, into the said pipes r1 and T2 through which the condensate returns, instead of into the rectifying-columns themselves. "In the pipes 21, z2 and z3 for the Huid there is'provlded, in each one, an adjusting cock with a scale. Finally, the apparatus is provided with the four coolers K1, K2, K3 and K4.

The apparatus is designed and adapted for use in the continuous separation of constituents of different boiling pointsfrom complex mixtures, such as benzene (benzol), toluene, petroleum, etc.

In the usual rectifying'column, the vapors produced by the boiling of the liquid which is being rectiied, rise upward through the column, and meet the condensate moving in the opposite direction, and there is an exchan e between theless easily volatilized constituents of the vapor and the more easily volatilized constituents of the condensate. In the present invention the recovery of the separate constituents of the mixture in a pure state is divided into stages.

Instead of attempting to directly obtain a pure product without any admlxtures of more or less volatile constituents, this new process tries in the first place to solve the much easier problem of purifying by rectiication the raw vapors in sucha manner that the portion remaining in the form of vapor consists only of the two or more most volatile constituents without any less vola-v tile constituents. Such a process can be carried on continuously without any difficulty, if the conditions are such that the resence in the condensate from the 4rectifymg column, of traces of the more volatile constituents is not regarded as a disadvantage.

The second part of the problem consists only in recovering from the preparatorilyrectied vapors, consisting only of two constituents, that one which has the higher boilingpoint, as a pure, final product, this separatlon being easily effected by means of a second special rectifying column.

The following description of the mode of operation of the apparatus illustrated in the drawing will enable the process to be clearly understood.

The apparatus illustrated in the drawing serves to separate a mixture of fluids containing four constituents of different boiling-temperatures, which may be designated 1, .2, 3 and l, 1 being the most volatile and 4 the least volatile constituent. The raw mixture of fluids consisting of these four constituents is introduced in an uninterrupted stream, preferably by a fluid-regulator not shown in "the drawing, through the pipe a1, provided with an adjusting-cock h, into the upper part of the distilling-column A1. This column has near its bottom a heater AV1, by which the fluids are thoroughly ascending vapors give up their less volatile l constituents to the fluid. In this way the preparatory separation can be energetically and thoroughly carried out, so that the fluid in passing out of the lower part of the contains o Vcelu-nm is uiteifree from constituent 1 and` y insignificant traces' of *.constltuent 2, while the vapors "coming out of the hood of thedistillin lcolumn A1 through the pipe alare; quite ee of constituent 4 vand consist of the whole of constituent "l, the greater part'of constituent 2, and a small admlxture of constituent 3; These vapors enter the loottoxnv partsothe rectifying-column' B1 and stream through the same from the bottom to the top; during this 'paage the vapors boil'the condensate, formed 1n theupper partfof the column out ofthemsate, the more .-v

. of the pure'constituents 1 and 2, while the` condensate owing down in the column consists of constituent 3 with an admixture of passin out of the hood of B1 are conducted constituent 2; this condensate is, after assing throuhevaporator BV1, conducted ack intofthe istilling column A4, through the pipefr-to b e treated anew, while the vapors throug the pipe b1 into av second rectifyingcolumn C1. In this second rectifying column .C1, the process isrepeated, with the difference lthat in' this column the procedure vis soconducted that rby the rectification, the

' reater part of the constituent 2 flows, as a dV condensate, free from any admixture of the most volatile constituent 1, from the lower part offthe column C1 through the xilpedinto the cooler K2, as a finished pure, alproduct, while the va ors-passing out of the column C1, through e pipe c1 in the .hood at the top, into the cooler K4, consist only of the pure constituent 1 mixed with a small part of constituent 2. The treat ment of this first foreliow, as recovered in the cooler K1, to obtain constituent 1, pure `and unmixed, is the subject of a' special process and need lnot here be further described. y

As has been described above, the preparatorily-cleaned fluid passing out of the distilling-column A1 through the pipe z2 consists onl of constitutents 3 and 4 with a small` a 'xture of constituent 2. This first afterflow passes for a further treatment into the second part of the apparatus,

which .exactly the saine as the first, consists of `a d1 stilling-column A2 and two rectifylng-columns B2 and C2. The rst afterflow passes luto the upper part of the distillingcolumn A2 top to the bottom; by the vapors develo ed out of this first afterflow in the heater 2 is effected a preparatory depurating of the Huid in the same manner as with the' distilling-column a1. The second lafterflovv? and through the same from the @come passing out of the'column A2 at`the bottom v consists-.only ofthe pure constituent 4 mixed .with slight traces of constituent 3, and is conducted throu h the pipe s into the cooler K,'in order to e submitted -later onto an rafter-treatment, 4for separating the-pure, unvmixed constituent 4,

.which is likewise no part otthe present invention. The vapors pa'ssinv out of the hoodiof the column A2 'throng the pipe a2 vconsist of constituent 3, vWith-,admixtures of constituents 2 and 4.

They enter vthe rectifying-column B2, in which, by rectiiication, a separation takes place in such a manner that the condensate which,v after ,passin through the evaporator BV2, is conducted ack through the ipe r2 in to the distillin -column A2 for a rther treatment, is per ectly freed'from constituent 2 and consists only of constituents 3 and (in small quantities) 4., while the vapors passing from the hood of the rectiymgcolumn B2 into the rectifying-column C2 are perfectl freed .from constituent 4 and consistv Aexc usively of the pure constituent 3 with a sli ht admiXture of constituent 2. In the rectiiyingcol'unm C2 is then repeated the process described with ,regard to the column Cl. From this column, the unmixed constituent 3,-as a pure, final product, low's i through the pipe d2 into the cooler K3, while from `the hood of the column C2 passes out, through the pipe c2, a second foreflow consisting of the complete remainder of constituent 2 with an admixture of constituent K `3, which has'remained in the vapors. This second foreflow is however not recovered like the first foreflow and the second afterflow, as an imperfect-ly-rectiied intermediate product, but is returned in the form of vapor to the rst rectiying column B1 for a further treatment.

The process thus makes it possible to recover in an uninterrupted process the two constituents of the raw fluid intermediate as to their boiling temperatures, as pure nal products without any admixtures. The apparatus illustrated inthe drawing may, of course, be enlarged by any number of main parts consisting each of one distilling-column and two rectifying-columns accordin to the number of constituents to be separatein a pure state out of a raw fluid by means of th1s process. A The arrangement of the apparatus by which any -number of similar units, eachA consisting of one distilling column and two rectiying columns, are connected together is new,--as is also the method of recovering pure, final products by rectification of intermediate roducts, obtained by preparatory rectification in a distilling and rectifying column.

As will be seen from the above description, the condensates formed in the rectifyturned for. fur-ther treatn-ient the distilling-columnsAl, A2.

In the treatment f fluids which evaporate at a low temperature, there is the drawback that -owing to exterior cooling there is formed in the rectifyin -col'umnsa greater quantity of condensate t an-requi'red for the rectification. It may easily happen that the rectifying-columns do not ossess4 the amount of heat required for oing their work, so that it isl diicult to keep the depurated vapors in avaporous state. This difficulty is remedied by the provision of an evaporator in the lower part of the rectifying column', s which furnishes a sufficient `quantity of heat to insure a thorough vapo,-

rization ofthe fluid under treatment, so that awell-purilied condensate only is returned to the distilling column.

The use of heaters Vfor the purpose of evaporating fluids in distilling or' rectifying-columns is known per se. But what is new is this intercalation of an eva orator into the return-conduit for the condensate formed in a rectifyin -column, through whichit returns intol a istilling-column intended for treating this condensate for the purpose of returning a part of the same in the form of vapor to the rectifying-column.

The useV of regulatable adjusting cocks is a feature which facilitates an undisturbed and uninterrupted working. In prior distilling columns, the outflow of the residual fluid from the distilling column has always been through an overflow-pipe, whose height is such that it corresponds with the pressure of the fluid during the process. `I/Vhen the outflowv of the residue is controlled in this way, the latter will continuously iiow out in `quantity corresponding to that of the fresh supply admitted to the distilling-column, less that part of the fresh supply which is evaporated by the distilling-column. On the supposition that the quantity of fresh supply and that the quantity of heat conveyed to the distilling-column remain always uninterruptedly uniform, and that also the working of the rectifying-column connected with the distilling column is not subject to any fluctuations, the residue passing out of such an overflow-pipe will always be of the same composition. By regulating the whole rocess by thev systems already known, it wou d therefore be possible, on the supposition that outside disturbances cannot occur, to obtain uninterruptedly a residue consisting only of pure, non-volatile ingredients, by' means of the device of asimpleV overflow-pipe. But this supposition of always avoiding disturbances in the working cannot possibly be fulfilled. Even when using the best automatically-working fluid and pressure regulators, it cannot be preventedpthat through the inattention of the man in charge of the working or through vtimes be abnormal. `when such dlsturbances occur, to regulate or outside disturbances, the conditions under which the process is carried outwill some- While it is possible readjust at oncel the working of the whole -plant, for the purpose of preventing deterioration of the nal product of the rectifying-column, this could notbe accom lished without influencing the quality'of t e less volatile constituents coming from the distilling column. This drawback is excluded by the new arrangement which consists in providing in the pipe through which the residue flows olf from the-distilling-column, an adjusting-cock, preferably provlded with ascale. This cock is during the process so adjusted that it only allows such quantity of the residue to pass out of the distillingcolumn .as will enable the desired composition `of the residue to be obtained, which may be ascertained by taking samples and testing.

I claim 1. A system for the continuous separation I from uid mixtures of constituents lof different boiling points, comprising (1 a dis-- tilling column provided with a con uit for delivering the vaporizedV products therefrom; (2) a rectifying column to which said conduit is connected, said rectifying column having an evaporative heater and a conduit leading from its lower portion to said distilling column and a conduit for delivering the vaporized products from its upper portion; and (8) a second rectifying column to which said last-mentioned conduit is connected, provided with means for collecting the vaporized product and the condensate. y

2. A system for the continuous separation from fluid mixtures of constituents of different boiling points, comprising (l) a distilling column provided with valved inlet and outlet pipes, and a conduit for delivering the .vaporized products therefrom; (2) a rectifying column to which said conduit is connected, said rectifying column having an evaporative heater and a conduit leading from its lower portion to said distilling column and a conduit for delivering the vaporized products from its upper portion; and (3) a second rectifying column to which said last-mentioned conduit is connected, provided with means for collecting the vaporized product and the condensate.

3. The combination with (l) a system comprising a distilling column, a rectifying column havin an evaporative heater, and

va-.second rectik ing column all connected in series,lof @(2) a second'system comprising a distilling column, airectifying column havin an evaporative heater, and a second recti ying column all connected in series, and (3) a conduit provided with a regulating valve, connecting the two distilling columns A tier oft e secon for delivering the etterdovv ofthev Erst column tothe second column.

4. The combination with' (l) n system comprising a distilling column, e rectlfyln column'havin an evaporative'heater, en

a second rec ing column all connected in seriesh of (2? a, second system comprising e,v

distillmg co umn, a rectlfyin column'hav- 'ing an eva orativeheater, an a second rec' 1o t1 in co umn all connected insel-ies', (3) a con uit provided with a regulating valve connecting -the two Ydistillin columns for delivering the afterilow of t e first column to the second column, and (4:) a, conduit connectin the vemr escape ofthe tinelrecsystemwith the first rectiy' column of the first system.

5. he process of treating a, complexliq- .uid vto separate Vconstituents of .dierent nennen fboilingvpointss which consists inheating the liquid in e' distilling column to vnporize a portion thereof, .conveying the va orized Eortionto a rectlfying coumn an there eating it to evaporate a part of the condensate, returning the unevaporeted portion ofthe condensate tothe distillmg column andconveying the va orized ortionA to a. second rectiztyin condensate there densingfthe vapori'zed portion.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

n. WALTHER iLGns.-

coumny co ecting the, om and separately con- 

